1,721,138 research outputs found
La teoria della struttura inerente di rete per lo studio dei sistemi elettrici ed elettronici per l'energia
No full textProbabilistic planning of a battery energy storage system in a hybrid microgrid based on the Taguchi arrays
Full text linkThe transformation of electrical networks in the context of the new smart grid paradigm unavoidably involves new challenges for electrical component planning. This paper provides a tool for the probabilistic sizing of a battery energy storage system in a hybrid AC/DC microgrid (i.e., a microgrid including AC and DC subsections with AC and DC loads and renewable power generation). The procedure is based on an analytical formulation to assess the total costs sustained by the microgrid for the inclusion of the battery energy storage system. The total costs depend on the random nature of the load demand, the electrical energy prices, and the renewable power generation, therefore, a probabilistic approach has been used. Furthermore, to account for uncertainties that affect the input data, the Taguchi orthogonal arrays are applied which allow significantly reducing the computational efforts while guaranteeing the desired accuracy of the results. The proposed analytical formulation along with the use of the Taguchi orthogonal arrays allows limiting the computational complexity even in presence of a large number of random inputs and discretization levels. A case study based on an industrial hybrid microgrid is presented to analyse the results obtained in terms of the optimal sizing of the battery energy storage system and to investigate the sensitivity with respect to some inputs
Determination of the prosumer's optimal bids
Full text linkThis paper considers a microgrid connected with
a medium-voltage (MV) distribution network. It is assumed
that the microgrid, which is managed by a prosumer,
operates in a competitive environment and participates
in the day-ahead market. Then, as the first step of the
short-term management problem, the prosumer must
determine the bids to be submitted to the market. The
offer strategy is based on the application of an optimization
model, which is solved for different hourly price
profiles of energy exchanged with the main grid. The
proposed procedure is applied to a microgrid and four
different its configurations were analyzed. The configurations
consider the presence of thermoelectric units that
only produce electricity, a boiler or/and cogeneration
power plants for the thermal loads, and an electric storage
system. The numerical results confirmed the numerous
theoretical considerations that have been made
Optimal multi-objective distribution system reconfiguration with multi criteria decision making-based solution ranking and enhanced genetic operators
No full textIn electrical distribution system optimisation, the presence of multiple conflicting objectives is effectively addressed by using Pareto front analysis. This paper deals with optimal reconfiguration considering network losses and energy not supplied as multi-objectives. A set of original contributions are provided with reference to the construction and updating of the best-known Pareto front using a genetic algorithm-based solver. The crossover operator is extended to address multi-objective solutions. The mutation operator is extended to handle a broader number of cases. Multi-objective solution ranking is applied by resorting to multi criteria decision making methods during the creation of the offsprings in the crossover operator, as well as to provide an automatic support for the decision maker to identify the preferable solution in the final Pareto front. The proposed approach is applied on two reference test networks, for which the complete Pareto front is calculated from the entire set of multi-objective solutions. The resulting best-known Pareto front is compared with the complete Pareto front using a metric based on geometrical considerations. This comparison framework is helpful to assess the performance of the multi-objective optimisation solvers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Trigeneration system planning based on decision theory
No full textEnergy system planning is a multi-year process with significant uncertainty embedded in the variables affecting the planning decisions. This large uncertainty calls for the adoption of techniques of analysis based on the definition of suitable scenarios and of their probability of occurrence indicated by the decision-maker. This paper addresses trigeneration system planning by applying a decision theory-based approach, considering the net present cost as economic indicator. The application of this method shows the convenience of setting up a combined generation system to serve the simultaneous demand of electricity, heating and cooling load
Attenuation of Harmonic Pollution due to the Adjustable Speed Drives in the Electric Circuits of the Power Plant Auxiliary Services
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